This invention relates to systems for automatic analysis of slides spotted with biological fluids such as blood and more particularly to a slide analysis system having novel slide transfer and liquid sample dispensing components for spotting a slide.
The analysis of biological fluid samples such as blood to help evaluate the health or well being of an individual is often carried out in test laboratories specially set up for fluid sample testing purposes. Thus, a blood sample that is withdrawn from a patient in a physician's office may be packed and shipped to a test facility, unless the physician's office is equipped with analytical apparatus for performing the desired tests. However in most cases, physicians' offices are not set up to perform detailed analyses of blood samples.
Thus an outside test facility performs selected tests on the blood sample, documenting the results in a report that is sent to the physician. A time lapse of several days or more may occur between blood sample procurement by the physician and the physician's receipt of the test report from the testing laboratory. In many instances such a delay can be crucial in the treatment of the patient's illness.
Timing is especially critical if a patient has an existing or emerging deleterious condition which is only detectable from a blood test and requires immediate treatment.
The sheer volume of blood testing that is carried out in laboratories or test facilities usually dictates the amount of time delay that will occur between receipt of a blood sample and the forwarding of a corresponding report to a physician. As more and more individuals request blood tests, there is the prospect of prolonged delays between sample procurement by a physician and the reporting of test results from test laboratories.
In response to the increasing demand for blood tests and the need for shorter turnaround times in reporting the test results, there has been a progressive development of apparatus for analyzing biological fluid samples. Such apparatus can process samples in relatively short periods of time and are relatively simple to operate. Some known apparatus typically perform diverse automatic analyses of fluid samples after such samples have been deposited on slides.
For example, U.S. Pat. Nos. 4,568,519; 4,512,952; 4,296,069 and 4,296,070 disclose systems and system components for automatic analysis of blood samples deposited on slides. The disclosed systems require a first slide transfer mechanism for moving slides relative to a slide supply device, a second slide transport device for transporting the slides to a metering device which spots the slides with the fluid sample, and a third slide transfer device for moving the spotted slides relative to an incubator device. The slide transfer mechanisms can include slide ejecting devices and slide feed devices for moving a slide from one location to another. Due to the intricacy, size requirements and expense of the systems disclosed in the foregoing patents, their use is warranted primarily in laboratories and specialized test facilities rather than a physician's office.
U.S. Pat. Nos. 4,452,899 and 4,675,301 show a metering head that automatically moves up and down as well as back and forth and carries a disposable pipette tip. An ejection device for removing the pipette tip from the metering device is spaced and separate from the metering head. Thus the ejection device is not built into the metering head and the metering head must be brought into alignment with the ejection device in order to eject the pipette tip.
It is thus desirable to provide a slide analysis system having a single multi-function slide transfer device for moving individual slides to several locations and a slide spotting device which accesses blood samples in a slide holding device, spots the slides with the accessed sample and has a built-in pipette tip ejector for automatically ejecting a used pipette tip when the testing of an individual fluid sample is completed.
It is further desirable to provide an automatic slide analysis system which is sufficiently compact to be utilized in a physician's office or a small laboratory and thus helps obviate the need by physicians or small laboratories to resort to specialized test facilities for all blood sample analyses.